// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#if V8_TARGET_ARCH_IA32

#include "src/base/bits.h"
#include "src/base/division-by-constant.h"
#include "src/base/utils/random-number-generator.h"
#include "src/bootstrapper.h"
#include "src/callable.h"
#include "src/code-factory.h"
#include "src/counters.h"
#include "src/debug/debug.h"
#include "src/external-reference-table.h"
#include "src/frame-constants.h"
#include "src/frames-inl.h"
#include "src/heap/heap-inl.h" // For MemoryChunk.
#include "src/ia32/assembler-ia32-inl.h"
#include "src/macro-assembler.h"
#include "src/runtime/runtime.h"
#include "src/snapshot/embedded-data.h"
#include "src/snapshot/snapshot.h"

// Satisfy cpplint check, but don't include platform-specific header. It is
// included recursively via macro-assembler.h.
#if 0
#include "src/ia32/macro-assembler-ia32.h"
#endif

namespace v8 {
namespace internal {

    // -------------------------------------------------------------------------
    // MacroAssembler implementation.

    void TurboAssembler::InitializeRootRegister()
    {
        ExternalReference isolate_root = ExternalReference::isolate_root(isolate());
        Move(kRootRegister, Immediate(isolate_root));
    }

    void TurboAssembler::LoadRoot(Register destination, RootIndex index)
    {
        if (root_array_available()) {
            mov(destination,
                Operand(kRootRegister, RootRegisterOffsetForRootIndex(index)));
            return;
        }

        if (RootsTable::IsImmortalImmovable(index)) {
            Handle<Object> object = isolate()->root_handle(index);
            if (object->IsSmi()) {
                mov(destination, Immediate(Smi::cast(*object)));
                return;
            } else {
                DCHECK(object->IsHeapObject());
                mov(destination, Handle<HeapObject>::cast(object));
                return;
            }
        }

        ExternalReference isolate_root = ExternalReference::isolate_root(isolate());
        lea(destination,
            Operand(isolate_root.address(), RelocInfo::EXTERNAL_REFERENCE));
        mov(destination, Operand(destination, RootRegisterOffsetForRootIndex(index)));
    }

    void TurboAssembler::CompareRoot(Register with, Register scratch,
        RootIndex index)
    {
        if (root_array_available()) {
            CompareRoot(with, index);
        } else {
            ExternalReference isolate_root = ExternalReference::isolate_root(isolate());
            lea(scratch,
                Operand(isolate_root.address(), RelocInfo::EXTERNAL_REFERENCE));
            cmp(with, Operand(scratch, RootRegisterOffsetForRootIndex(index)));
        }
    }

    void TurboAssembler::CompareRoot(Register with, RootIndex index)
    {
        if (root_array_available()) {
            cmp(with, Operand(kRootRegister, RootRegisterOffsetForRootIndex(index)));
            return;
        }

        DCHECK(RootsTable::IsImmortalImmovable(index));
        Handle<Object> object = isolate()->root_handle(index);
        if (object->IsHeapObject()) {
            cmp(with, Handle<HeapObject>::cast(object));
        } else {
            cmp(with, Immediate(Smi::cast(*object)));
        }
    }

    void TurboAssembler::CompareStackLimit(Register with)
    {
        if (root_array_available()) {
            CompareRoot(with, RootIndex::kStackLimit);
        } else {
            DCHECK(!options().isolate_independent_code);
            ExternalReference ref = ExternalReference::address_of_stack_limit(isolate());
            cmp(with, Operand(ref.address(), RelocInfo::EXTERNAL_REFERENCE));
        }
    }

    void TurboAssembler::CompareRealStackLimit(Register with)
    {
        if (root_array_available()) {
            CompareRoot(with, RootIndex::kRealStackLimit);
        } else {
            DCHECK(!options().isolate_independent_code);
            ExternalReference ref = ExternalReference::address_of_real_stack_limit(isolate());
            cmp(with, Operand(ref.address(), RelocInfo::EXTERNAL_REFERENCE));
        }
    }

    void MacroAssembler::PushRoot(RootIndex index)
    {
        if (root_array_available()) {
            DCHECK(RootsTable::IsImmortalImmovable(index));
            push(Operand(kRootRegister, RootRegisterOffsetForRootIndex(index)));
            return;
        }

        // TODO(v8:6666): Add a scratch register or remove all uses.
        DCHECK(RootsTable::IsImmortalImmovable(index));
        Handle<Object> object = isolate()->root_handle(index);
        if (object->IsHeapObject()) {
            Push(Handle<HeapObject>::cast(object));
        } else {
            Push(Smi::cast(*object));
        }
    }

    void MacroAssembler::JumpIfIsInRange(Register value, unsigned lower_limit,
        unsigned higher_limit, Register scratch,
        Label* on_in_range,
        Label::Distance near_jump)
    {
        if (lower_limit != 0) {
            lea(scratch, Operand(value, 0u - lower_limit));
            cmp(scratch, Immediate(higher_limit - lower_limit));
        } else {
            cmp(value, Immediate(higher_limit));
        }
        j(below_equal, on_in_range, near_jump);
    }

    Operand TurboAssembler::ExternalReferenceAsOperand(ExternalReference reference,
        Register scratch)
    {
        // TODO(jgruber): Add support for enable_root_array_delta_access.
        if (root_array_available() && options().isolate_independent_code) {
            if (IsAddressableThroughRootRegister(isolate(), reference)) {
                // Some external references can be efficiently loaded as an offset from
                // kRootRegister.
                intptr_t offset = RootRegisterOffsetForExternalReference(isolate(), reference);
                return Operand(kRootRegister, offset);
            } else {
                // Otherwise, do a memory load from the external reference table.
                mov(scratch, Operand(kRootRegister, RootRegisterOffsetForExternalReferenceTableEntry(isolate(), reference)));
                return Operand(scratch, 0);
            }
        }
        Move(scratch, Immediate(reference));
        return Operand(scratch, 0);
    }

    // TODO(v8:6666): If possible, refactor into a platform-independent function in
    // TurboAssembler.
    Operand TurboAssembler::ExternalReferenceAddressAsOperand(
        ExternalReference reference)
    {
        DCHECK(FLAG_embedded_builtins);
        DCHECK(root_array_available());
        DCHECK(options().isolate_independent_code);
        return Operand(
            kRootRegister,
            RootRegisterOffsetForExternalReferenceTableEntry(isolate(), reference));
    }

    // TODO(v8:6666): If possible, refactor into a platform-independent function in
    // TurboAssembler.
    Operand TurboAssembler::HeapObjectAsOperand(Handle<HeapObject> object)
    {
        DCHECK(FLAG_embedded_builtins);
        DCHECK(root_array_available());

        int builtin_index;
        RootIndex root_index;
        if (isolate()->roots_table().IsRootHandle(object, &root_index)) {
            return Operand(kRootRegister, RootRegisterOffsetForRootIndex(root_index));
        } else if (isolate()->builtins()->IsBuiltinHandle(object, &builtin_index)) {
            return Operand(kRootRegister,
                RootRegisterOffsetForBuiltinIndex(builtin_index));
        } else if (object.is_identical_to(code_object_) && Builtins::IsBuiltinId(maybe_builtin_index_)) {
            return Operand(kRootRegister,
                RootRegisterOffsetForBuiltinIndex(maybe_builtin_index_));
        } else {
            // Objects in the constants table need an additional indirection, which
            // cannot be represented as a single Operand.
            UNREACHABLE();
        }
    }

    void TurboAssembler::LoadFromConstantsTable(Register destination,
        int constant_index)
    {
        DCHECK(RootsTable::IsImmortalImmovable(RootIndex::kBuiltinsConstantsTable));
        LoadRoot(destination, RootIndex::kBuiltinsConstantsTable);
        mov(destination,
            FieldOperand(destination, FixedArray::OffsetOfElementAt(constant_index)));
    }

    void TurboAssembler::LoadRootRegisterOffset(Register destination,
        intptr_t offset)
    {
        DCHECK(is_int32(offset));
        DCHECK(root_array_available());
        if (offset == 0) {
            mov(destination, kRootRegister);
        } else {
            lea(destination, Operand(kRootRegister, static_cast<int32_t>(offset)));
        }
    }

    void TurboAssembler::LoadRootRelative(Register destination, int32_t offset)
    {
        DCHECK(root_array_available());
        mov(destination, Operand(kRootRegister, offset));
    }

    void TurboAssembler::LoadAddress(Register destination,
        ExternalReference source)
    {
        // TODO(jgruber): Add support for enable_root_array_delta_access.
        if (root_array_available() && options().isolate_independent_code) {
            IndirectLoadExternalReference(destination, source);
            return;
        }
        mov(destination, Immediate(source));
    }

    static constexpr Register saved_regs[] = { eax, ecx, edx };

    static constexpr int kNumberOfSavedRegs = sizeof(saved_regs) / sizeof(Register);

    int TurboAssembler::RequiredStackSizeForCallerSaved(SaveFPRegsMode fp_mode,
        Register exclusion1,
        Register exclusion2,
        Register exclusion3) const
    {
        int bytes = 0;
        for (int i = 0; i < kNumberOfSavedRegs; i++) {
            Register reg = saved_regs[i];
            if (reg != exclusion1 && reg != exclusion2 && reg != exclusion3) {
                bytes += kSystemPointerSize;
            }
        }

        if (fp_mode == kSaveFPRegs) {
            // Count all XMM registers except XMM0.
            bytes += kDoubleSize * (XMMRegister::kNumRegisters - 1);
        }

        return bytes;
    }

    int TurboAssembler::PushCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
        Register exclusion2, Register exclusion3)
    {
        // We don't allow a GC during a store buffer overflow so there is no need to
        // store the registers in any particular way, but we do have to store and
        // restore them.
        int bytes = 0;
        for (int i = 0; i < kNumberOfSavedRegs; i++) {
            Register reg = saved_regs[i];
            if (reg != exclusion1 && reg != exclusion2 && reg != exclusion3) {
                push(reg);
                bytes += kSystemPointerSize;
            }
        }

        if (fp_mode == kSaveFPRegs) {
            // Save all XMM registers except XMM0.
            int delta = kDoubleSize * (XMMRegister::kNumRegisters - 1);
            sub(esp, Immediate(delta));
            for (int i = XMMRegister::kNumRegisters - 1; i > 0; i--) {
                XMMRegister reg = XMMRegister::from_code(i);
                movsd(Operand(esp, (i - 1) * kDoubleSize), reg);
            }
            bytes += delta;
        }

        return bytes;
    }

    int TurboAssembler::PopCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
        Register exclusion2, Register exclusion3)
    {
        int bytes = 0;
        if (fp_mode == kSaveFPRegs) {
            // Restore all XMM registers except XMM0.
            int delta = kDoubleSize * (XMMRegister::kNumRegisters - 1);
            for (int i = XMMRegister::kNumRegisters - 1; i > 0; i--) {
                XMMRegister reg = XMMRegister::from_code(i);
                movsd(reg, Operand(esp, (i - 1) * kDoubleSize));
            }
            add(esp, Immediate(delta));
            bytes += delta;
        }

        for (int i = kNumberOfSavedRegs - 1; i >= 0; i--) {
            Register reg = saved_regs[i];
            if (reg != exclusion1 && reg != exclusion2 && reg != exclusion3) {
                pop(reg);
                bytes += kSystemPointerSize;
            }
        }

        return bytes;
    }

    void MacroAssembler::DoubleToI(Register result_reg, XMMRegister input_reg,
        XMMRegister scratch, Label* lost_precision,
        Label* is_nan, Label::Distance dst)
    {
        DCHECK(input_reg != scratch);
        cvttsd2si(result_reg, Operand(input_reg));
        Cvtsi2sd(scratch, Operand(result_reg));
        ucomisd(scratch, input_reg);
        j(not_equal, lost_precision, dst);
        j(parity_even, is_nan, dst);
    }

    void MacroAssembler::RecordWriteField(Register object, int offset,
        Register value, Register dst,
        SaveFPRegsMode save_fp,
        RememberedSetAction remembered_set_action,
        SmiCheck smi_check)
    {
        // First, check if a write barrier is even needed. The tests below
        // catch stores of Smis.
        Label done;

        // Skip barrier if writing a smi.
        if (smi_check == INLINE_SMI_CHECK) {
            JumpIfSmi(value, &done);
        }

        // Although the object register is tagged, the offset is relative to the start
        // of the object, so so offset must be a multiple of kTaggedSize.
        DCHECK(IsAligned(offset, kTaggedSize));

        lea(dst, FieldOperand(object, offset));
        if (emit_debug_code()) {
            Label ok;
            test_b(dst, Immediate(kTaggedSize - 1));
            j(zero, &ok, Label::kNear);
            int3();
            bind(&ok);
        }

        RecordWrite(object, dst, value, save_fp, remembered_set_action,
            OMIT_SMI_CHECK);

        bind(&done);

        // Clobber clobbered input registers when running with the debug-code flag
        // turned on to provoke errors.
        if (emit_debug_code()) {
            mov(value, Immediate(bit_cast<int32_t>(kZapValue)));
            mov(dst, Immediate(bit_cast<int32_t>(kZapValue)));
        }
    }

    void TurboAssembler::SaveRegisters(RegList registers)
    {
        DCHECK_GT(NumRegs(registers), 0);
        for (int i = 0; i < Register::kNumRegisters; ++i) {
            if ((registers >> i) & 1u) {
                push(Register::from_code(i));
            }
        }
    }

    void TurboAssembler::RestoreRegisters(RegList registers)
    {
        DCHECK_GT(NumRegs(registers), 0);
        for (int i = Register::kNumRegisters - 1; i >= 0; --i) {
            if ((registers >> i) & 1u) {
                pop(Register::from_code(i));
            }
        }
    }

    void TurboAssembler::CallEphemeronKeyBarrier(Register object, Register address,
        SaveFPRegsMode fp_mode)
    {
        EphemeronKeyBarrierDescriptor descriptor;
        RegList registers = descriptor.allocatable_registers();

        SaveRegisters(registers);

        Register object_parameter(
            descriptor.GetRegisterParameter(EphemeronKeyBarrierDescriptor::kObject));
        Register slot_parameter(descriptor.GetRegisterParameter(
            EphemeronKeyBarrierDescriptor::kSlotAddress));
        Register fp_mode_parameter(
            descriptor.GetRegisterParameter(EphemeronKeyBarrierDescriptor::kFPMode));

        push(object);
        push(address);

        pop(slot_parameter);
        pop(object_parameter);

        Move(fp_mode_parameter, Smi::FromEnum(fp_mode));
        Call(isolate()->builtins()->builtin_handle(Builtins::kEphemeronKeyBarrier),
            RelocInfo::CODE_TARGET);

        RestoreRegisters(registers);
    }

    void TurboAssembler::CallRecordWriteStub(
        Register object, Register address,
        RememberedSetAction remembered_set_action, SaveFPRegsMode fp_mode)
    {
        CallRecordWriteStub(
            object, address, remembered_set_action, fp_mode,
            isolate()->builtins()->builtin_handle(Builtins::kRecordWrite),
            kNullAddress);
    }

    void TurboAssembler::CallRecordWriteStub(
        Register object, Register address,
        RememberedSetAction remembered_set_action, SaveFPRegsMode fp_mode,
        Address wasm_target)
    {
        CallRecordWriteStub(object, address, remembered_set_action, fp_mode,
            Handle<Code>::null(), wasm_target);
    }

    void TurboAssembler::CallRecordWriteStub(
        Register object, Register address,
        RememberedSetAction remembered_set_action, SaveFPRegsMode fp_mode,
        Handle<Code> code_target, Address wasm_target)
    {
        DCHECK_NE(code_target.is_null(), wasm_target == kNullAddress);
        // TODO(albertnetymk): For now we ignore remembered_set_action and fp_mode,
        // i.e. always emit remember set and save FP registers in RecordWriteStub. If
        // large performance regression is observed, we should use these values to
        // avoid unnecessary work.

        RecordWriteDescriptor descriptor;
        RegList registers = descriptor.allocatable_registers();

        SaveRegisters(registers);

        Register object_parameter(
            descriptor.GetRegisterParameter(RecordWriteDescriptor::kObject));
        Register slot_parameter(
            descriptor.GetRegisterParameter(RecordWriteDescriptor::kSlot));
        Register remembered_set_parameter(
            descriptor.GetRegisterParameter(RecordWriteDescriptor::kRememberedSet));
        Register fp_mode_parameter(
            descriptor.GetRegisterParameter(RecordWriteDescriptor::kFPMode));

        push(object);
        push(address);

        pop(slot_parameter);
        pop(object_parameter);

        Move(remembered_set_parameter, Smi::FromEnum(remembered_set_action));
        Move(fp_mode_parameter, Smi::FromEnum(fp_mode));
        if (code_target.is_null()) {
            // Use {wasm_call} for direct Wasm call within a module.
            wasm_call(wasm_target, RelocInfo::WASM_STUB_CALL);
        } else {
            Call(code_target, RelocInfo::CODE_TARGET);
        }

        RestoreRegisters(registers);
    }

    void MacroAssembler::RecordWrite(Register object, Register address,
        Register value, SaveFPRegsMode fp_mode,
        RememberedSetAction remembered_set_action,
        SmiCheck smi_check)
    {
        DCHECK(object != value);
        DCHECK(object != address);
        DCHECK(value != address);
        AssertNotSmi(object);

        if (remembered_set_action == OMIT_REMEMBERED_SET && !FLAG_incremental_marking) {
            return;
        }

        if (emit_debug_code()) {
            Label ok;
            cmp(value, Operand(address, 0));
            j(equal, &ok, Label::kNear);
            int3();
            bind(&ok);
        }

        // First, check if a write barrier is even needed. The tests below
        // catch stores of Smis and stores into young gen.
        Label done;

        if (smi_check == INLINE_SMI_CHECK) {
            // Skip barrier if writing a smi.
            JumpIfSmi(value, &done, Label::kNear);
        }

        CheckPageFlag(value,
            value, // Used as scratch.
            MemoryChunk::kPointersToHereAreInterestingMask, zero, &done,
            Label::kNear);
        CheckPageFlag(object,
            value, // Used as scratch.
            MemoryChunk::kPointersFromHereAreInterestingMask,
            zero,
            &done,
            Label::kNear);

        CallRecordWriteStub(object, address, remembered_set_action, fp_mode);

        bind(&done);

        // Clobber clobbered registers when running with the debug-code flag
        // turned on to provoke errors.
        if (emit_debug_code()) {
            mov(address, Immediate(bit_cast<int32_t>(kZapValue)));
            mov(value, Immediate(bit_cast<int32_t>(kZapValue)));
        }
    }

    void MacroAssembler::MaybeDropFrames()
    {
        // Check whether we need to drop frames to restart a function on the stack.
        Label dont_drop;
        ExternalReference restart_fp = ExternalReference::debug_restart_fp_address(isolate());
        mov(eax, ExternalReferenceAsOperand(restart_fp, eax));
        test(eax, eax);
        j(zero, &dont_drop, Label::kNear);

        Jump(BUILTIN_CODE(isolate(), FrameDropperTrampoline), RelocInfo::CODE_TARGET);
        bind(&dont_drop);
    }

    void TurboAssembler::Cvtsi2ss(XMMRegister dst, Operand src)
    {
        xorps(dst, dst);
        cvtsi2ss(dst, src);
    }

    void TurboAssembler::Cvtsi2sd(XMMRegister dst, Operand src)
    {
        xorpd(dst, dst);
        cvtsi2sd(dst, src);
    }

    void TurboAssembler::Cvtui2ss(XMMRegister dst, Operand src, Register tmp)
    {
        Label done;
        Register src_reg = src.is_reg_only() ? src.reg() : tmp;
        if (src_reg == tmp)
            mov(tmp, src);
        cvtsi2ss(dst, src_reg);
        test(src_reg, src_reg);
        j(positive, &done, Label::kNear);

        // Compute {src/2 | (src&1)} (retain the LSB to avoid rounding errors).
        if (src_reg != tmp)
            mov(tmp, src_reg);
        shr(tmp, 1);
        // The LSB is shifted into CF. If it is set, set the LSB in {tmp}.
        Label msb_not_set;
        j(not_carry, &msb_not_set, Label::kNear);
        or_(tmp, Immediate(1));
        bind(&msb_not_set);
        cvtsi2ss(dst, tmp);
        addss(dst, dst);
        bind(&done);
    }

    void TurboAssembler::Cvttss2ui(Register dst, Operand src, XMMRegister tmp)
    {
        Label done;
        cvttss2si(dst, src);
        test(dst, dst);
        j(positive, &done);
        Move(tmp, static_cast<float>(INT32_MIN));
        addss(tmp, src);
        cvttss2si(dst, tmp);
        or_(dst, Immediate(0x80000000));
        bind(&done);
    }

    void TurboAssembler::Cvtui2sd(XMMRegister dst, Operand src, Register scratch)
    {
        Label done;
        cmp(src, Immediate(0));
        ExternalReference uint32_bias = ExternalReference::address_of_uint32_bias();
        Cvtsi2sd(dst, src);
        j(not_sign, &done, Label::kNear);
        addsd(dst, ExternalReferenceAsOperand(uint32_bias, scratch));
        bind(&done);
    }

    void TurboAssembler::Cvttsd2ui(Register dst, Operand src, XMMRegister tmp)
    {
        Move(tmp, -2147483648.0);
        addsd(tmp, src);
        cvttsd2si(dst, tmp);
        add(dst, Immediate(0x80000000));
    }

    void TurboAssembler::ShlPair(Register high, Register low, uint8_t shift)
    {
        if (shift >= 32) {
            mov(high, low);
            shl(high, shift - 32);
            xor_(low, low);
        } else {
            shld(high, low, shift);
            shl(low, shift);
        }
    }

    void TurboAssembler::ShlPair_cl(Register high, Register low)
    {
        shld_cl(high, low);
        shl_cl(low);
        Label done;
        test(ecx, Immediate(0x20));
        j(equal, &done, Label::kNear);
        mov(high, low);
        xor_(low, low);
        bind(&done);
    }

    void TurboAssembler::ShrPair(Register high, Register low, uint8_t shift)
    {
        if (shift >= 32) {
            mov(low, high);
            shr(low, shift - 32);
            xor_(high, high);
        } else {
            shrd(high, low, shift);
            shr(high, shift);
        }
    }

    void TurboAssembler::ShrPair_cl(Register high, Register low)
    {
        shrd_cl(low, high);
        shr_cl(high);
        Label done;
        test(ecx, Immediate(0x20));
        j(equal, &done, Label::kNear);
        mov(low, high);
        xor_(high, high);
        bind(&done);
    }

    void TurboAssembler::SarPair(Register high, Register low, uint8_t shift)
    {
        if (shift >= 32) {
            mov(low, high);
            sar(low, shift - 32);
            sar(high, 31);
        } else {
            shrd(high, low, shift);
            sar(high, shift);
        }
    }

    void TurboAssembler::SarPair_cl(Register high, Register low)
    {
        shrd_cl(low, high);
        sar_cl(high);
        Label done;
        test(ecx, Immediate(0x20));
        j(equal, &done, Label::kNear);
        mov(low, high);
        sar(high, 31);
        bind(&done);
    }

    void MacroAssembler::CmpObjectType(Register heap_object,
        InstanceType type,
        Register map)
    {
        mov(map, FieldOperand(heap_object, HeapObject::kMapOffset));
        CmpInstanceType(map, type);
    }

    void MacroAssembler::CmpInstanceType(Register map, InstanceType type)
    {
        cmpw(FieldOperand(map, Map::kInstanceTypeOffset), Immediate(type));
    }

    void MacroAssembler::AssertSmi(Register object)
    {
        if (emit_debug_code()) {
            test(object, Immediate(kSmiTagMask));
            Check(equal, AbortReason::kOperandIsNotASmi);
        }
    }

    void MacroAssembler::AssertConstructor(Register object)
    {
        if (emit_debug_code()) {
            test(object, Immediate(kSmiTagMask));
            Check(not_equal, AbortReason::kOperandIsASmiAndNotAConstructor);
            Push(object);
            mov(object, FieldOperand(object, HeapObject::kMapOffset));
            test_b(FieldOperand(object, Map::kBitFieldOffset),
                Immediate(Map::IsConstructorBit::kMask));
            Pop(object);
            Check(not_zero, AbortReason::kOperandIsNotAConstructor);
        }
    }

    void MacroAssembler::AssertFunction(Register object)
    {
        if (emit_debug_code()) {
            test(object, Immediate(kSmiTagMask));
            Check(not_equal, AbortReason::kOperandIsASmiAndNotAFunction);
            Push(object);
            CmpObjectType(object, JS_FUNCTION_TYPE, object);
            Pop(object);
            Check(equal, AbortReason::kOperandIsNotAFunction);
        }
    }

    void MacroAssembler::AssertBoundFunction(Register object)
    {
        if (emit_debug_code()) {
            test(object, Immediate(kSmiTagMask));
            Check(not_equal, AbortReason::kOperandIsASmiAndNotABoundFunction);
            Push(object);
            CmpObjectType(object, JS_BOUND_FUNCTION_TYPE, object);
            Pop(object);
            Check(equal, AbortReason::kOperandIsNotABoundFunction);
        }
    }

    void MacroAssembler::AssertGeneratorObject(Register object)
    {
        if (!emit_debug_code())
            return;

        test(object, Immediate(kSmiTagMask));
        Check(not_equal, AbortReason::kOperandIsASmiAndNotAGeneratorObject);

        {
            Push(object);
            Register map = object;

            // Load map
            mov(map, FieldOperand(object, HeapObject::kMapOffset));

            Label do_check;
            // Check if JSGeneratorObject
            CmpInstanceType(map, JS_GENERATOR_OBJECT_TYPE);
            j(equal, &do_check, Label::kNear);

            // Check if JSAsyncFunctionObject.
            CmpInstanceType(map, JS_ASYNC_FUNCTION_OBJECT_TYPE);
            j(equal, &do_check, Label::kNear);

            // Check if JSAsyncGeneratorObject
            CmpInstanceType(map, JS_ASYNC_GENERATOR_OBJECT_TYPE);

            bind(&do_check);
            Pop(object);
        }

        Check(equal, AbortReason::kOperandIsNotAGeneratorObject);
    }

    void MacroAssembler::AssertUndefinedOrAllocationSite(Register object,
        Register scratch)
    {
        if (emit_debug_code()) {
            Label done_checking;
            AssertNotSmi(object);
            CompareRoot(object, scratch, RootIndex::kUndefinedValue);
            j(equal, &done_checking);
            LoadRoot(scratch, RootIndex::kAllocationSiteWithWeakNextMap);
            cmp(FieldOperand(object, 0), scratch);
            Assert(equal, AbortReason::kExpectedUndefinedOrCell);
            bind(&done_checking);
        }
    }

    void MacroAssembler::AssertNotSmi(Register object)
    {
        if (emit_debug_code()) {
            test(object, Immediate(kSmiTagMask));
            Check(not_equal, AbortReason::kOperandIsASmi);
        }
    }

    void TurboAssembler::StubPrologue(StackFrame::Type type)
    {
        push(ebp); // Caller's frame pointer.
        mov(ebp, esp);
        push(Immediate(StackFrame::TypeToMarker(type)));
    }

    void TurboAssembler::Prologue()
    {
        push(ebp); // Caller's frame pointer.
        mov(ebp, esp);
        push(esi); // Callee's context.
        push(edi); // Callee's JS function.
    }

    void TurboAssembler::EnterFrame(StackFrame::Type type)
    {
        push(ebp);
        mov(ebp, esp);
        push(Immediate(StackFrame::TypeToMarker(type)));
    }

    void TurboAssembler::LeaveFrame(StackFrame::Type type)
    {
        if (emit_debug_code()) {
            cmp(Operand(ebp, CommonFrameConstants::kContextOrFrameTypeOffset),
                Immediate(StackFrame::TypeToMarker(type)));
            Check(equal, AbortReason::kStackFrameTypesMustMatch);
        }
        leave();
    }

#ifdef V8_OS_WIN
    void TurboAssembler::AllocateStackFrame(Register bytes_scratch)
    {
        // In windows, we cannot increment the stack size by more than one page
        // (minimum page size is 4KB) without accessing at least one byte on the
        // page. Check this:
        // https://msdn.microsoft.com/en-us/library/aa227153(v=vs.60).aspx.
        constexpr int kPageSize = 4 * 1024;
        Label check_offset;
        Label touch_next_page;
        jmp(&check_offset);
        bind(&touch_next_page);
        sub(esp, Immediate(kPageSize));
        // Just to touch the page, before we increment further.
        mov(Operand(esp, 0), Immediate(0));
        sub(bytes_scratch, Immediate(kPageSize));

        bind(&check_offset);
        cmp(bytes_scratch, kPageSize);
        j(greater, &touch_next_page);

        sub(esp, bytes_scratch);
    }
#endif

    void MacroAssembler::EnterExitFramePrologue(StackFrame::Type frame_type,
        Register scratch)
    {
        DCHECK(frame_type == StackFrame::EXIT || frame_type == StackFrame::BUILTIN_EXIT);

        // Set up the frame structure on the stack.
        DCHECK_EQ(+2 * kSystemPointerSize, ExitFrameConstants::kCallerSPDisplacement);
        DCHECK_EQ(+1 * kSystemPointerSize, ExitFrameConstants::kCallerPCOffset);
        DCHECK_EQ(0 * kSystemPointerSize, ExitFrameConstants::kCallerFPOffset);
        push(ebp);
        mov(ebp, esp);

        // Reserve room for entry stack pointer.
        push(Immediate(StackFrame::TypeToMarker(frame_type)));
        DCHECK_EQ(-2 * kSystemPointerSize, ExitFrameConstants::kSPOffset);
        push(Immediate(0)); // Saved entry sp, patched before call.

        STATIC_ASSERT(edx == kRuntimeCallFunctionRegister);
        STATIC_ASSERT(esi == kContextRegister);

        // Save the frame pointer and the context in top.
        ExternalReference c_entry_fp_address = ExternalReference::Create(IsolateAddressId::kCEntryFPAddress, isolate());
        ExternalReference context_address = ExternalReference::Create(IsolateAddressId::kContextAddress, isolate());
        ExternalReference c_function_address = ExternalReference::Create(IsolateAddressId::kCFunctionAddress, isolate());

        DCHECK(!AreAliased(scratch, ebp, esi, edx));
        mov(ExternalReferenceAsOperand(c_entry_fp_address, scratch), ebp);
        mov(ExternalReferenceAsOperand(context_address, scratch), esi);
        mov(ExternalReferenceAsOperand(c_function_address, scratch), edx);
    }

    void MacroAssembler::EnterExitFrameEpilogue(int argc, bool save_doubles)
    {
        // Optionally save all XMM registers.
        if (save_doubles) {
            int space = XMMRegister::kNumRegisters * kDoubleSize + argc * kSystemPointerSize;
            sub(esp, Immediate(space));
            const int offset = -ExitFrameConstants::kFixedFrameSizeFromFp;
            for (int i = 0; i < XMMRegister::kNumRegisters; i++) {
                XMMRegister reg = XMMRegister::from_code(i);
                movsd(Operand(ebp, offset - ((i + 1) * kDoubleSize)), reg);
            }
        } else {
            sub(esp, Immediate(argc * kSystemPointerSize));
        }

        // Get the required frame alignment for the OS.
        const int kFrameAlignment = base::OS::ActivationFrameAlignment();
        if (kFrameAlignment > 0) {
            DCHECK(base::bits::IsPowerOfTwo(kFrameAlignment));
            and_(esp, -kFrameAlignment);
        }

        // Patch the saved entry sp.
        mov(Operand(ebp, ExitFrameConstants::kSPOffset), esp);
    }

    void MacroAssembler::EnterExitFrame(int argc, bool save_doubles,
        StackFrame::Type frame_type)
    {
        EnterExitFramePrologue(frame_type, edi);

        // Set up argc and argv in callee-saved registers.
        int offset = StandardFrameConstants::kCallerSPOffset - kSystemPointerSize;
        mov(edi, eax);
        lea(esi, Operand(ebp, eax, times_system_pointer_size, offset));

        // Reserve space for argc, argv and isolate.
        EnterExitFrameEpilogue(argc, save_doubles);
    }

    void MacroAssembler::EnterApiExitFrame(int argc, Register scratch)
    {
        EnterExitFramePrologue(StackFrame::EXIT, scratch);
        EnterExitFrameEpilogue(argc, false);
    }

    void MacroAssembler::LeaveExitFrame(bool save_doubles, bool pop_arguments)
    {
        // Optionally restore all XMM registers.
        if (save_doubles) {
            const int offset = -ExitFrameConstants::kFixedFrameSizeFromFp;
            for (int i = 0; i < XMMRegister::kNumRegisters; i++) {
                XMMRegister reg = XMMRegister::from_code(i);
                movsd(reg, Operand(ebp, offset - ((i + 1) * kDoubleSize)));
            }
        }

        if (pop_arguments) {
            // Get the return address from the stack and restore the frame pointer.
            mov(ecx, Operand(ebp, 1 * kSystemPointerSize));
            mov(ebp, Operand(ebp, 0 * kSystemPointerSize));

            // Pop the arguments and the receiver from the caller stack.
            lea(esp, Operand(esi, 1 * kSystemPointerSize));

            // Push the return address to get ready to return.
            push(ecx);
        } else {
            // Otherwise just leave the exit frame.
            leave();
        }

        LeaveExitFrameEpilogue();
    }

    void MacroAssembler::LeaveExitFrameEpilogue()
    {
        // Clear the top frame.
        ExternalReference c_entry_fp_address = ExternalReference::Create(IsolateAddressId::kCEntryFPAddress, isolate());
        mov(ExternalReferenceAsOperand(c_entry_fp_address, esi), Immediate(0));

        // Restore current context from top and clear it in debug mode.
        ExternalReference context_address = ExternalReference::Create(IsolateAddressId::kContextAddress, isolate());
        mov(esi, ExternalReferenceAsOperand(context_address, esi));
#ifdef DEBUG
        push(eax);
        mov(ExternalReferenceAsOperand(context_address, eax),
            Immediate(Context::kInvalidContext));
        pop(eax);
#endif
    }

    void MacroAssembler::LeaveApiExitFrame()
    {
        mov(esp, ebp);
        pop(ebp);

        LeaveExitFrameEpilogue();
    }

    void MacroAssembler::PushStackHandler(Register scratch)
    {
        // Adjust this code if not the case.
        STATIC_ASSERT(StackHandlerConstants::kSize == 2 * kSystemPointerSize);
        STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0);

        push(Immediate(0)); // Padding.

        // Link the current handler as the next handler.
        ExternalReference handler_address = ExternalReference::Create(IsolateAddressId::kHandlerAddress, isolate());
        push(ExternalReferenceAsOperand(handler_address, scratch));

        // Set this new handler as the current one.
        mov(ExternalReferenceAsOperand(handler_address, scratch), esp);
    }

    void MacroAssembler::PopStackHandler(Register scratch)
    {
        STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0);
        ExternalReference handler_address = ExternalReference::Create(IsolateAddressId::kHandlerAddress, isolate());
        pop(ExternalReferenceAsOperand(handler_address, scratch));
        add(esp, Immediate(StackHandlerConstants::kSize - kSystemPointerSize));
    }

    void MacroAssembler::CallRuntime(const Runtime::Function* f,
        int num_arguments,
        SaveFPRegsMode save_doubles)
    {
        // If the expected number of arguments of the runtime function is
        // constant, we check that the actual number of arguments match the
        // expectation.
        CHECK(f->nargs < 0 || f->nargs == num_arguments);

        // TODO(1236192): Most runtime routines don't need the number of
        // arguments passed in because it is constant. At some point we
        // should remove this need and make the runtime routine entry code
        // smarter.
        Move(kRuntimeCallArgCountRegister, Immediate(num_arguments));
        Move(kRuntimeCallFunctionRegister, Immediate(ExternalReference::Create(f)));
        Handle<Code> code = CodeFactory::CEntry(isolate(), f->result_size, save_doubles);
        Call(code, RelocInfo::CODE_TARGET);
    }

    void TurboAssembler::CallRuntimeWithCEntry(Runtime::FunctionId fid,
        Register centry)
    {
        const Runtime::Function* f = Runtime::FunctionForId(fid);
        // TODO(1236192): Most runtime routines don't need the number of
        // arguments passed in because it is constant. At some point we
        // should remove this need and make the runtime routine entry code
        // smarter.
        Move(kRuntimeCallArgCountRegister, Immediate(f->nargs));
        Move(kRuntimeCallFunctionRegister, Immediate(ExternalReference::Create(f)));
        DCHECK(!AreAliased(centry, kRuntimeCallArgCountRegister,
            kRuntimeCallFunctionRegister));
        CallCodeObject(centry);
    }

    void MacroAssembler::TailCallRuntime(Runtime::FunctionId fid)
    {
        // ----------- S t a t e -------------
        //  -- esp[0]                 : return address
        //  -- esp[8]                 : argument num_arguments - 1
        //  ...
        //  -- esp[8 * num_arguments] : argument 0 (receiver)
        //
        //  For runtime functions with variable arguments:
        //  -- eax                    : number of  arguments
        // -----------------------------------

        const Runtime::Function* function = Runtime::FunctionForId(fid);
        DCHECK_EQ(1, function->result_size);
        if (function->nargs >= 0) {
            // TODO(1236192): Most runtime routines don't need the number of
            // arguments passed in because it is constant. At some point we
            // should remove this need and make the runtime routine entry code
            // smarter.
            Move(kRuntimeCallArgCountRegister, Immediate(function->nargs));
        }
        JumpToExternalReference(ExternalReference::Create(fid));
    }

    void MacroAssembler::JumpToExternalReference(const ExternalReference& ext,
        bool builtin_exit_frame)
    {
        // Set the entry point and jump to the C entry runtime stub.
        Move(kRuntimeCallFunctionRegister, Immediate(ext));
        Handle<Code> code = CodeFactory::CEntry(isolate(), 1, kDontSaveFPRegs,
            kArgvOnStack, builtin_exit_frame);
        Jump(code, RelocInfo::CODE_TARGET);
    }

    void MacroAssembler::JumpToInstructionStream(Address entry)
    {
        jmp(entry, RelocInfo::OFF_HEAP_TARGET);
    }

    void TurboAssembler::PrepareForTailCall(
        const ParameterCount& callee_args_count, Register caller_args_count_reg,
        Register scratch0, Register scratch1,
        int number_of_temp_values_after_return_address)
    {
#if DEBUG
        if (callee_args_count.is_reg()) {
            DCHECK(!AreAliased(callee_args_count.reg(), caller_args_count_reg, scratch0,
                scratch1));
        } else {
            DCHECK(!AreAliased(caller_args_count_reg, scratch0, scratch1));
        }
#endif

        // Calculate the destination address where we will put the return address
        // after we drop current frame.
        Register new_sp_reg = scratch0;
        if (callee_args_count.is_reg()) {
            sub(caller_args_count_reg, callee_args_count.reg());
            lea(new_sp_reg,
                Operand(ebp, caller_args_count_reg, times_system_pointer_size,
                    StandardFrameConstants::kCallerPCOffset - number_of_temp_values_after_return_address * kSystemPointerSize));
        } else {
            lea(new_sp_reg,
                Operand(ebp, caller_args_count_reg, times_system_pointer_size,
                    StandardFrameConstants::kCallerPCOffset - (callee_args_count.immediate() + number_of_temp_values_after_return_address) * kSystemPointerSize));
        }

        if (FLAG_debug_code) {
            cmp(esp, new_sp_reg);
            Check(below, AbortReason::kStackAccessBelowStackPointer);
        }

        // Copy return address from caller's frame to current frame's return address
        // to avoid its trashing and let the following loop copy it to the right
        // place.
        Register tmp_reg = scratch1;
        mov(tmp_reg, Operand(ebp, StandardFrameConstants::kCallerPCOffset));
        mov(Operand(esp,
                number_of_temp_values_after_return_address * kSystemPointerSize),
            tmp_reg);

        // Restore caller's frame pointer now as it could be overwritten by
        // the copying loop.
        mov(ebp, Operand(ebp, StandardFrameConstants::kCallerFPOffset));

        // +2 here is to copy both receiver and return address.
        Register count_reg = caller_args_count_reg;
        if (callee_args_count.is_reg()) {
            lea(count_reg, Operand(callee_args_count.reg(), 2 + number_of_temp_values_after_return_address));
        } else {
            mov(count_reg, Immediate(callee_args_count.immediate() + 2 + number_of_temp_values_after_return_address));
            // TODO(ishell): Unroll copying loop for small immediate values.
        }

        // Now copy callee arguments to the caller frame going backwards to avoid
        // callee arguments corruption (source and destination areas could overlap).
        Label loop, entry;
        jmp(&entry, Label::kNear);
        bind(&loop);
        dec(count_reg);
        mov(tmp_reg, Operand(esp, count_reg, times_system_pointer_size, 0));
        mov(Operand(new_sp_reg, count_reg, times_system_pointer_size, 0), tmp_reg);
        bind(&entry);
        cmp(count_reg, Immediate(0));
        j(not_equal, &loop, Label::kNear);

        // Leave current frame.
        mov(esp, new_sp_reg);
    }

    void MacroAssembler::InvokePrologue(const ParameterCount& expected,
        const ParameterCount& actual, Label* done,
        bool* definitely_mismatches,
        InvokeFlag flag,
        Label::Distance done_near)
    {
        DCHECK_IMPLIES(expected.is_reg(), expected.reg() == ecx);
        DCHECK_IMPLIES(actual.is_reg(), actual.reg() == eax);

        bool definitely_matches = false;
        *definitely_mismatches = false;
        Label invoke;
        if (expected.is_immediate()) {
            DCHECK(actual.is_immediate());
            mov(eax, actual.immediate());
            if (expected.immediate() == actual.immediate()) {
                definitely_matches = true;
            } else {
                const int sentinel = SharedFunctionInfo::kDontAdaptArgumentsSentinel;
                if (expected.immediate() == sentinel) {
                    // Don't worry about adapting arguments for builtins that
                    // don't want that done. Skip adaption code by making it look
                    // like we have a match between expected and actual number of
                    // arguments.
                    definitely_matches = true;
                } else {
                    *definitely_mismatches = true;
                    mov(ecx, expected.immediate());
                }
            }
        } else {
            if (actual.is_immediate()) {
                // Expected is in register, actual is immediate. This is the
                // case when we invoke function values without going through the
                // IC mechanism.
                mov(eax, actual.immediate());
                cmp(expected.reg(), actual.immediate());
                j(equal, &invoke);
                DCHECK(expected.reg() == ecx);
            } else if (expected.reg() != actual.reg()) {
                // Both expected and actual are in (different) registers. This
                // is the case when we invoke functions using call and apply.
                cmp(expected.reg(), actual.reg());
                j(equal, &invoke);
                DCHECK(actual.reg() == eax);
                DCHECK(expected.reg() == ecx);
            } else {
                definitely_matches = true;
                Move(eax, actual.reg());
            }
        }

        if (!definitely_matches) {
            Handle<Code> adaptor = BUILTIN_CODE(isolate(), ArgumentsAdaptorTrampoline);
            if (flag == CALL_FUNCTION) {
                Call(adaptor, RelocInfo::CODE_TARGET);
                if (!*definitely_mismatches) {
                    jmp(done, done_near);
                }
            } else {
                Jump(adaptor, RelocInfo::CODE_TARGET);
            }
            bind(&invoke);
        }
    }

    void MacroAssembler::CheckDebugHook(Register fun, Register new_target,
        const ParameterCount& expected,
        const ParameterCount& actual)
    {
        Label skip_hook;

        ExternalReference debug_hook_active = ExternalReference::debug_hook_on_function_call_address(isolate());
        push(eax);
        cmpb(ExternalReferenceAsOperand(debug_hook_active, eax), Immediate(0));
        pop(eax);
        j(equal, &skip_hook);

        {
            FrameScope frame(this,
                has_frame() ? StackFrame::NONE : StackFrame::INTERNAL);
            if (expected.is_reg()) {
                SmiTag(expected.reg());
                Push(expected.reg());
            }
            if (actual.is_reg()) {
                SmiTag(actual.reg());
                Push(actual.reg());
                SmiUntag(actual.reg());
            }
            if (new_target.is_valid()) {
                Push(new_target);
            }
            Push(fun);
            Push(fun);
            Operand receiver_op = actual.is_reg()
                ? Operand(ebp, actual.reg(), times_system_pointer_size,
                    kSystemPointerSize * 2)
                : Operand(ebp, actual.immediate() * times_system_pointer_size + kSystemPointerSize * 2);
            Push(receiver_op);
            CallRuntime(Runtime::kDebugOnFunctionCall);
            Pop(fun);
            if (new_target.is_valid()) {
                Pop(new_target);
            }
            if (actual.is_reg()) {
                Pop(actual.reg());
                SmiUntag(actual.reg());
            }
            if (expected.is_reg()) {
                Pop(expected.reg());
                SmiUntag(expected.reg());
            }
        }
        bind(&skip_hook);
    }

    void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
        const ParameterCount& expected,
        const ParameterCount& actual,
        InvokeFlag flag)
    {
        // You can't call a function without a valid frame.
        DCHECK(flag == JUMP_FUNCTION || has_frame());
        DCHECK(function == edi);
        DCHECK_IMPLIES(new_target.is_valid(), new_target == edx);
        DCHECK_IMPLIES(expected.is_reg(), expected.reg() == ecx);
        DCHECK_IMPLIES(actual.is_reg(), actual.reg() == eax);

        // On function call, call into the debugger if necessary.
        CheckDebugHook(function, new_target, expected, actual);

        // Clear the new.target register if not given.
        if (!new_target.is_valid()) {
            Move(edx, isolate()->factory()->undefined_value());
        }

        Label done;
        bool definitely_mismatches = false;
        InvokePrologue(expected, actual, &done, &definitely_mismatches, flag,
            Label::kNear);
        if (!definitely_mismatches) {
            // We call indirectly through the code field in the function to
            // allow recompilation to take effect without changing any of the
            // call sites.
            static_assert(kJavaScriptCallCodeStartRegister == ecx, "ABI mismatch");
            mov(ecx, FieldOperand(function, JSFunction::kCodeOffset));
            if (flag == CALL_FUNCTION) {
                CallCodeObject(ecx);
            } else {
                DCHECK(flag == JUMP_FUNCTION);
                JumpCodeObject(ecx);
            }
            bind(&done);
        }
    }

    void MacroAssembler::InvokeFunction(Register fun, Register new_target,
        const ParameterCount& actual,
        InvokeFlag flag)
    {
        // You can't call a function without a valid frame.
        DCHECK(flag == JUMP_FUNCTION || has_frame());

        DCHECK(fun == edi);
        mov(ecx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
        mov(esi, FieldOperand(edi, JSFunction::kContextOffset));
        movzx_w(ecx,
            FieldOperand(ecx, SharedFunctionInfo::kFormalParameterCountOffset));

        ParameterCount expected(ecx);
        InvokeFunctionCode(edi, new_target, expected, actual, flag);
    }

    void MacroAssembler::LoadGlobalProxy(Register dst)
    {
        mov(dst, NativeContextOperand());
        mov(dst, ContextOperand(dst, Context::GLOBAL_PROXY_INDEX));
    }

    void MacroAssembler::LoadGlobalFunction(int index, Register function)
    {
        // Load the native context from the current context.
        mov(function, NativeContextOperand());
        // Load the function from the native context.
        mov(function, ContextOperand(function, index));
    }

    int MacroAssembler::SafepointRegisterStackIndex(int reg_code)
    {
        // The registers are pushed starting with the lowest encoding,
        // which means that lowest encodings are furthest away from
        // the stack pointer.
        DCHECK(reg_code >= 0 && reg_code < kNumSafepointRegisters);
        return kNumSafepointRegisters - reg_code - 1;
    }

    void TurboAssembler::Ret() { ret(0); }

    void TurboAssembler::Ret(int bytes_dropped, Register scratch)
    {
        if (is_uint16(bytes_dropped)) {
            ret(bytes_dropped);
        } else {
            pop(scratch);
            add(esp, Immediate(bytes_dropped));
            push(scratch);
            ret(0);
        }
    }

    void TurboAssembler::Push(Immediate value)
    {
        if (root_array_available() && options().isolate_independent_code) {
            if (value.is_embedded_object()) {
                Push(HeapObjectAsOperand(value.embedded_object()));
                return;
            } else if (value.is_external_reference()) {
                Push(ExternalReferenceAddressAsOperand(value.external_reference()));
                return;
            }
        }
        push(value);
    }

    void MacroAssembler::Drop(int stack_elements)
    {
        if (stack_elements > 0) {
            add(esp, Immediate(stack_elements * kSystemPointerSize));
        }
    }

    void TurboAssembler::Move(Register dst, Register src)
    {
        if (dst != src) {
            mov(dst, src);
        }
    }

    void TurboAssembler::Move(Register dst, const Immediate& src)
    {
        if (!src.is_heap_object_request() && src.is_zero()) {
            xor_(dst, dst); // Shorter than mov of 32-bit immediate 0.
        } else if (src.is_external_reference()) {
            LoadAddress(dst, src.external_reference());
        } else {
            mov(dst, src);
        }
    }

    void TurboAssembler::Move(Operand dst, const Immediate& src)
    {
        // Since there's no scratch register available, take a detour through the
        // stack.
        if (root_array_available() && options().isolate_independent_code) {
            if (src.is_embedded_object() || src.is_external_reference() || src.is_heap_object_request()) {
                Push(src);
                pop(dst);
                return;
            }
        }

        if (src.is_embedded_object()) {
            mov(dst, src.embedded_object());
        } else {
            mov(dst, src);
        }
    }

    void TurboAssembler::Move(Register dst, Handle<HeapObject> src)
    {
        if (root_array_available() && options().isolate_independent_code) {
            IndirectLoadConstant(dst, src);
            return;
        }
        mov(dst, src);
    }

    void TurboAssembler::Move(XMMRegister dst, uint32_t src)
    {
        if (src == 0) {
            pxor(dst, dst);
        } else {
            unsigned cnt = base::bits::CountPopulation(src);
            unsigned nlz = base::bits::CountLeadingZeros32(src);
            unsigned ntz = base::bits::CountTrailingZeros32(src);
            if (nlz + cnt + ntz == 32) {
                pcmpeqd(dst, dst);
                if (ntz == 0) {
                    psrld(dst, 32 - cnt);
                } else {
                    pslld(dst, 32 - cnt);
                    if (nlz != 0)
                        psrld(dst, nlz);
                }
            } else {
                push(eax);
                mov(eax, Immediate(src));
                movd(dst, Operand(eax));
                pop(eax);
            }
        }
    }

    void TurboAssembler::Move(XMMRegister dst, uint64_t src)
    {
        if (src == 0) {
            pxor(dst, dst);
        } else {
            uint32_t lower = static_cast<uint32_t>(src);
            uint32_t upper = static_cast<uint32_t>(src >> 32);
            unsigned cnt = base::bits::CountPopulation(src);
            unsigned nlz = base::bits::CountLeadingZeros64(src);
            unsigned ntz = base::bits::CountTrailingZeros64(src);
            if (nlz + cnt + ntz == 64) {
                pcmpeqd(dst, dst);
                if (ntz == 0) {
                    psrlq(dst, 64 - cnt);
                } else {
                    psllq(dst, 64 - cnt);
                    if (nlz != 0)
                        psrlq(dst, nlz);
                }
            } else if (lower == 0) {
                Move(dst, upper);
                psllq(dst, 32);
            } else if (CpuFeatures::IsSupported(SSE4_1)) {
                CpuFeatureScope scope(this, SSE4_1);
                push(eax);
                Move(eax, Immediate(lower));
                movd(dst, Operand(eax));
                if (upper != lower) {
                    Move(eax, Immediate(upper));
                }
                pinsrd(dst, Operand(eax), 1);
                pop(eax);
            } else {
                push(Immediate(upper));
                push(Immediate(lower));
                movsd(dst, Operand(esp, 0));
                add(esp, Immediate(kDoubleSize));
            }
        }
    }

    void TurboAssembler::Pshufhw(XMMRegister dst, Operand src, uint8_t shuffle)
    {
        if (CpuFeatures::IsSupported(AVX)) {
            CpuFeatureScope scope(this, AVX);
            vpshufhw(dst, src, shuffle);
        } else {
            pshufhw(dst, src, shuffle);
        }
    }

    void TurboAssembler::Pshuflw(XMMRegister dst, Operand src, uint8_t shuffle)
    {
        if (CpuFeatures::IsSupported(AVX)) {
            CpuFeatureScope scope(this, AVX);
            vpshuflw(dst, src, shuffle);
        } else {
            pshuflw(dst, src, shuffle);
        }
    }

    void TurboAssembler::Pshufd(XMMRegister dst, Operand src, uint8_t shuffle)
    {
        if (CpuFeatures::IsSupported(AVX)) {
            CpuFeatureScope scope(this, AVX);
            vpshufd(dst, src, shuffle);
        } else {
            pshufd(dst, src, shuffle);
        }
    }

    void TurboAssembler::Psraw(XMMRegister dst, uint8_t shift)
    {
        if (CpuFeatures::IsSupported(AVX)) {
            CpuFeatureScope scope(this, AVX);
            vpsraw(dst, dst, shift);
        } else {
            psraw(dst, shift);
        }
    }

    void TurboAssembler::Psrlw(XMMRegister dst, uint8_t shift)
    {
        if (CpuFeatures::IsSupported(AVX)) {
            CpuFeatureScope scope(this, AVX);
            vpsrlw(dst, dst, shift);
        } else {
            psrlw(dst, shift);
        }
    }

    void TurboAssembler::Psignb(XMMRegister dst, Operand src)
    {
        if (CpuFeatures::IsSupported(AVX)) {
            CpuFeatureScope scope(this, AVX);
            vpsignb(dst, dst, src);
            return;
        }
        if (CpuFeatures::IsSupported(SSSE3)) {
            CpuFeatureScope sse_scope(this, SSSE3);
            psignb(dst, src);
            return;
        }
        FATAL("no AVX or SSE3 support");
    }

    void TurboAssembler::Psignw(XMMRegister dst, Operand src)
    {
        if (CpuFeatures::IsSupported(AVX)) {
            CpuFeatureScope scope(this, AVX);
            vpsignw(dst, dst, src);
            return;
        }
        if (CpuFeatures::IsSupported(SSSE3)) {
            CpuFeatureScope sse_scope(this, SSSE3);
            psignw(dst, src);
            return;
        }
        FATAL("no AVX or SSE3 support");
    }

    void TurboAssembler::Psignd(XMMRegister dst, Operand src)
    {
        if (CpuFeatures::IsSupported(AVX)) {
            CpuFeatureScope scope(this, AVX);
            vpsignd(dst, dst, src);
            return;
        }
        if (CpuFeatures::IsSupported(SSSE3)) {
            CpuFeatureScope sse_scope(this, SSSE3);
            psignd(dst, src);
            return;
        }
        FATAL("no AVX or SSE3 support");
    }

    void TurboAssembler::Pshufb(XMMRegister dst, Operand src)
    {
        if (CpuFeatures::IsSupported(AVX)) {
            CpuFeatureScope scope(this, AVX);
            vpshufb(dst, dst, src);
            return;
        }
        if (CpuFeatures::IsSupported(SSSE3)) {
            CpuFeatureScope sse_scope(this, SSSE3);
            pshufb(dst, src);
            return;
        }
        FATAL("no AVX or SSE3 support");
    }

    void TurboAssembler::Pblendw(XMMRegister dst, Operand src, uint8_t imm8)
    {
        if (CpuFeatures::IsSupported(AVX)) {
            CpuFeatureScope scope(this, AVX);
            vpblendw(dst, dst, src, imm8);
            return;
        }
        if (CpuFeatures::IsSupported(SSE4_1)) {
            CpuFeatureScope sse_scope(this, SSE4_1);
            pblendw(dst, src, imm8);
            return;
        }
        FATAL("no AVX or SSE4.1 support");
    }

    void TurboAssembler::Palignr(XMMRegister dst, Operand src, uint8_t imm8)
    {
        if (CpuFeatures::IsSupported(AVX)) {
            CpuFeatureScope scope(this, AVX);
            vpalignr(dst, dst, src, imm8);
            return;
        }
        if (CpuFeatures::IsSupported(SSSE3)) {
            CpuFeatureScope sse_scope(this, SSSE3);
            palignr(dst, src, imm8);
            return;
        }
        FATAL("no AVX or SSE3 support");
    }

    void TurboAssembler::Pextrb(Register dst, XMMRegister src, uint8_t imm8)
    {
        if (CpuFeatures::IsSupported(AVX)) {
            CpuFeatureScope scope(this, AVX);
            vpextrb(dst, src, imm8);
            return;
        }
        if (CpuFeatures::IsSupported(SSE4_1)) {
            CpuFeatureScope sse_scope(this, SSE4_1);
            pextrb(dst, src, imm8);
            return;
        }
        FATAL("no AVX or SSE4.1 support");
    }

    void TurboAssembler::Pextrw(Register dst, XMMRegister src, uint8_t imm8)
    {
        if (CpuFeatures::IsSupported(AVX)) {
            CpuFeatureScope scope(this, AVX);
            vpextrw(dst, src, imm8);
            return;
        }
        if (CpuFeatures::IsSupported(SSE4_1)) {
            CpuFeatureScope sse_scope(this, SSE4_1);
            pextrw(dst, src, imm8);
            return;
        }
        FATAL("no AVX or SSE4.1 support");
    }

    void TurboAssembler::Pextrd(Register dst, XMMRegister src, uint8_t imm8)
    {
        if (imm8 == 0) {
            Movd(dst, src);
            return;
        }
        if (CpuFeatures::IsSupported(AVX)) {
            CpuFeatureScope scope(this, AVX);
            vpextrd(dst, src, imm8);
            return;
        }
        if (CpuFeatures::IsSupported(SSE4_1)) {
            CpuFeatureScope sse_scope(this, SSE4_1);
            pextrd(dst, src, imm8);
            return;
        }
        // Without AVX or SSE, we can only have 64-bit values in xmm registers.
        // We don't have an xmm scratch register, so move the data via the stack. This
        // path is rarely required, so it's acceptable to be slow.
        DCHECK_LT(imm8, 2);
        sub(esp, Immediate(kDoubleSize));
        movsd(Operand(esp, 0), src);
        mov(dst, Operand(esp, imm8 * kUInt32Size));
        add(esp, Immediate(kDoubleSize));
    }

    void TurboAssembler::Pinsrd(XMMRegister dst, Operand src, uint8_t imm8)
    {
        if (CpuFeatures::IsSupported(AVX)) {
            CpuFeatureScope scope(this, AVX);
            vpinsrd(dst, dst, src, imm8);
            return;
        }
        if (CpuFeatures::IsSupported(SSE4_1)) {
            CpuFeatureScope sse_scope(this, SSE4_1);
            pinsrd(dst, src, imm8);
            return;
        }
        // Without AVX or SSE, we can only have 64-bit values in xmm registers.
        // We don't have an xmm scratch register, so move the data via the stack. This
        // path is rarely required, so it's acceptable to be slow.
        DCHECK_LT(imm8, 2);
        sub(esp, Immediate(kDoubleSize));
        // Write original content of {dst} to the stack.
        movsd(Operand(esp, 0), dst);
        // Overwrite the portion specified in {imm8}.
        if (src.is_reg_only()) {
            mov(Operand(esp, imm8 * kUInt32Size), src.reg());
        } else {
            movss(dst, src);
            movss(Operand(esp, imm8 * kUInt32Size), dst);
        }
        // Load back the full value into {dst}.
        movsd(dst, Operand(esp, 0));
        add(esp, Immediate(kDoubleSize));
    }

    void TurboAssembler::Lzcnt(Register dst, Operand src)
    {
        if (CpuFeatures::IsSupported(LZCNT)) {
            CpuFeatureScope scope(this, LZCNT);
            lzcnt(dst, src);
            return;
        }
        Label not_zero_src;
        bsr(dst, src);
        j(not_zero, &not_zero_src, Label::kNear);
        Move(dst, Immediate(63)); // 63^31 == 32
        bind(&not_zero_src);
        xor_(dst, Immediate(31)); // for x in [0..31], 31^x == 31-x.
    }

    void TurboAssembler::Tzcnt(Register dst, Operand src)
    {
        if (CpuFeatures::IsSupported(BMI1)) {
            CpuFeatureScope scope(this, BMI1);
            tzcnt(dst, src);
            return;
        }
        Label not_zero_src;
        bsf(dst, src);
        j(not_zero, &not_zero_src, Label::kNear);
        Move(dst, Immediate(32)); // The result of tzcnt is 32 if src = 0.
        bind(&not_zero_src);
    }

    void TurboAssembler::Popcnt(Register dst, Operand src)
    {
        if (CpuFeatures::IsSupported(POPCNT)) {
            CpuFeatureScope scope(this, POPCNT);
            popcnt(dst, src);
            return;
        }
        FATAL("no POPCNT support");
    }

    void MacroAssembler::LoadWeakValue(Register in_out, Label* target_if_cleared)
    {
        cmp(in_out, Immediate(kClearedWeakHeapObjectLower32));
        j(equal, target_if_cleared);

        and_(in_out, Immediate(~kWeakHeapObjectMask));
    }

    void MacroAssembler::IncrementCounter(StatsCounter* counter, int value,
        Register scratch)
    {
        DCHECK_GT(value, 0);
        if (FLAG_native_code_counters && counter->Enabled()) {
            Operand operand = ExternalReferenceAsOperand(ExternalReference::Create(counter), scratch);
            if (value == 1) {
                inc(operand);
            } else {
                add(operand, Immediate(value));
            }
        }
    }

    void MacroAssembler::DecrementCounter(StatsCounter* counter, int value,
        Register scratch)
    {
        DCHECK_GT(value, 0);
        if (FLAG_native_code_counters && counter->Enabled()) {
            Operand operand = ExternalReferenceAsOperand(ExternalReference::Create(counter), scratch);
            if (value == 1) {
                dec(operand);
            } else {
                sub(operand, Immediate(value));
            }
        }
    }

    void TurboAssembler::Assert(Condition cc, AbortReason reason)
    {
        if (emit_debug_code())
            Check(cc, reason);
    }

    void TurboAssembler::AssertUnreachable(AbortReason reason)
    {
        if (emit_debug_code())
            Abort(reason);
    }

    void TurboAssembler::Check(Condition cc, AbortReason reason)
    {
        Label L;
        j(cc, &L);
        Abort(reason);
        // will not return here
        bind(&L);
    }

    void TurboAssembler::CheckStackAlignment()
    {
        int frame_alignment = base::OS::ActivationFrameAlignment();
        int frame_alignment_mask = frame_alignment - 1;
        if (frame_alignment > kSystemPointerSize) {
            DCHECK(base::bits::IsPowerOfTwo(frame_alignment));
            Label alignment_as_expected;
            test(esp, Immediate(frame_alignment_mask));
            j(zero, &alignment_as_expected);
            // Abort if stack is not aligned.
            int3();
            bind(&alignment_as_expected);
        }
    }

    void TurboAssembler::Abort(AbortReason reason)
    {
#ifdef DEBUG
        const char* msg = GetAbortReason(reason);
        RecordComment("Abort message: ");
        RecordComment(msg);
#endif

        // Avoid emitting call to builtin if requested.
        if (trap_on_abort()) {
            int3();
            return;
        }

        if (should_abort_hard()) {
            // We don't care if we constructed a frame. Just pretend we did.
            FrameScope assume_frame(this, StackFrame::NONE);
            PrepareCallCFunction(1, eax);
            mov(Operand(esp, 0), Immediate(static_cast<int>(reason)));
            CallCFunction(ExternalReference::abort_with_reason(), 1);
            return;
        }

        Move(edx, Smi::FromInt(static_cast<int>(reason)));

        // Disable stub call restrictions to always allow calls to abort.
        if (!has_frame()) {
            // We don't actually want to generate a pile of code for this, so just
            // claim there is a stack frame, without generating one.
            FrameScope scope(this, StackFrame::NONE);
            Call(BUILTIN_CODE(isolate(), Abort), RelocInfo::CODE_TARGET);
        } else {
            Call(BUILTIN_CODE(isolate(), Abort), RelocInfo::CODE_TARGET);
        }
        // will not return here
        int3();
    }

    void TurboAssembler::PrepareCallCFunction(int num_arguments, Register scratch)
    {
        int frame_alignment = base::OS::ActivationFrameAlignment();
        if (frame_alignment != 0) {
            // Make stack end at alignment and make room for num_arguments words
            // and the original value of esp.
            mov(scratch, esp);
            sub(esp, Immediate((num_arguments + 1) * kSystemPointerSize));
            DCHECK(base::bits::IsPowerOfTwo(frame_alignment));
            and_(esp, -frame_alignment);
            mov(Operand(esp, num_arguments * kSystemPointerSize), scratch);
        } else {
            sub(esp, Immediate(num_arguments * kSystemPointerSize));
        }
    }

    void TurboAssembler::CallCFunction(ExternalReference function,
        int num_arguments)
    {
        // Trashing eax is ok as it will be the return value.
        Move(eax, Immediate(function));
        CallCFunction(eax, num_arguments);
    }

    void TurboAssembler::CallCFunction(Register function, int num_arguments)
    {
        DCHECK_LE(num_arguments, kMaxCParameters);
        DCHECK(has_frame());
        // Check stack alignment.
        if (emit_debug_code()) {
            CheckStackAlignment();
        }

        // Save the frame pointer and PC so that the stack layout remains iterable,
        // even without an ExitFrame which normally exists between JS and C frames.
        if (isolate() != nullptr) {
            // Get the current PC via call, pop. This gets the return address pushed to
            // the stack by call.
            Label get_pc;
            call(&get_pc);
            bind(&get_pc);
            // Find two caller-saved scratch registers.
            Register scratch1 = eax;
            Register scratch2 = ecx;
            if (function == eax)
                scratch1 = edx;
            if (function == ecx)
                scratch2 = edx;
            pop(scratch1);
            mov(ExternalReferenceAsOperand(
                    ExternalReference::fast_c_call_caller_pc_address(isolate()),
                    scratch2),
                scratch1);
            mov(ExternalReferenceAsOperand(
                    ExternalReference::fast_c_call_caller_fp_address(isolate()),
                    scratch2),
                ebp);
        }

        call(function);

        if (isolate() != nullptr) {
            // We don't unset the PC; the FP is the source of truth.
            mov(ExternalReferenceAsOperand(
                    ExternalReference::fast_c_call_caller_fp_address(isolate()), edx),
                Immediate(0));
        }

        if (base::OS::ActivationFrameAlignment() != 0) {
            mov(esp, Operand(esp, num_arguments * kSystemPointerSize));
        } else {
            add(esp, Immediate(num_arguments * kSystemPointerSize));
        }
    }

    void TurboAssembler::Call(Handle<Code> code_object, RelocInfo::Mode rmode)
    {
        DCHECK_IMPLIES(options().isolate_independent_code,
            Builtins::IsIsolateIndependentBuiltin(*code_object));
        if (options().inline_offheap_trampolines) {
            int builtin_index = Builtins::kNoBuiltinId;
            if (isolate()->builtins()->IsBuiltinHandle(code_object, &builtin_index) && Builtins::IsIsolateIndependent(builtin_index)) {
                // Inline the trampoline.
                RecordCommentForOffHeapTrampoline(builtin_index);
                CHECK_NE(builtin_index, Builtins::kNoBuiltinId);
                EmbeddedData d = EmbeddedData::FromBlob();
                Address entry = d.InstructionStartOfBuiltin(builtin_index);
                call(entry, RelocInfo::OFF_HEAP_TARGET);
                return;
            }
        }
        DCHECK(RelocInfo::IsCodeTarget(rmode));
        call(code_object, rmode);
    }

    void TurboAssembler::CallBuiltinPointer(Register builtin_pointer)
    {
        STATIC_ASSERT(kSystemPointerSize == 4);
        STATIC_ASSERT(kSmiShiftSize == 0);
        STATIC_ASSERT(kSmiTagSize == 1);
        STATIC_ASSERT(kSmiTag == 0);

        // The builtin_pointer register contains the builtin index as a Smi.
        // Untagging is folded into the indexing operand below (we use
        // times_half_system_pointer_size instead of times_system_pointer_size since
        // smis are already shifted by one).
        mov(builtin_pointer,
            Operand(kRootRegister, builtin_pointer, times_half_system_pointer_size,
                IsolateData::builtin_entry_table_offset()));
        call(builtin_pointer);
    }

    void TurboAssembler::LoadCodeObjectEntry(Register destination,
        Register code_object)
    {
        // Code objects are called differently depending on whether we are generating
        // builtin code (which will later be embedded into the binary) or compiling
        // user JS code at runtime.
        // * Builtin code runs in --jitless mode and thus must not call into on-heap
        //   Code targets. Instead, we dispatch through the builtins entry table.
        // * Codegen at runtime does not have this restriction and we can use the
        //   shorter, branchless instruction sequence. The assumption here is that
        //   targets are usually generated code and not builtin Code objects.

        if (options().isolate_independent_code) {
            DCHECK(root_array_available());
            Label if_code_is_off_heap, out;

            // Check whether the Code object is an off-heap trampoline. If so, call its
            // (off-heap) entry point directly without going through the (on-heap)
            // trampoline.  Otherwise, just call the Code object as always.
            test(FieldOperand(code_object, Code::kFlagsOffset),
                Immediate(Code::IsOffHeapTrampoline::kMask));
            j(not_equal, &if_code_is_off_heap);

            // Not an off-heap trampoline, the entry point is at
            // Code::raw_instruction_start().
            Move(destination, code_object);
            add(destination, Immediate(Code::kHeaderSize - kHeapObjectTag));
            jmp(&out);

            // An off-heap trampoline, the entry point is loaded from the builtin entry
            // table.
            bind(&if_code_is_off_heap);
            mov(destination, FieldOperand(code_object, Code::kBuiltinIndexOffset));
            mov(destination,
                Operand(kRootRegister, destination, times_system_pointer_size,
                    IsolateData::builtin_entry_table_offset()));

            bind(&out);
        } else {
            Move(destination, code_object);
            add(destination, Immediate(Code::kHeaderSize - kHeapObjectTag));
        }
    }

    void TurboAssembler::CallCodeObject(Register code_object)
    {
        LoadCodeObjectEntry(code_object, code_object);
        call(code_object);
    }

    void TurboAssembler::JumpCodeObject(Register code_object)
    {
        LoadCodeObjectEntry(code_object, code_object);
        jmp(code_object);
    }

    void TurboAssembler::Jump(Handle<Code> code_object, RelocInfo::Mode rmode)
    {
        DCHECK_IMPLIES(options().isolate_independent_code,
            Builtins::IsIsolateIndependentBuiltin(*code_object));
        if (options().inline_offheap_trampolines) {
            int builtin_index = Builtins::kNoBuiltinId;
            if (isolate()->builtins()->IsBuiltinHandle(code_object, &builtin_index) && Builtins::IsIsolateIndependent(builtin_index)) {
                // Inline the trampoline.
                RecordCommentForOffHeapTrampoline(builtin_index);
                CHECK_NE(builtin_index, Builtins::kNoBuiltinId);
                EmbeddedData d = EmbeddedData::FromBlob();
                Address entry = d.InstructionStartOfBuiltin(builtin_index);
                jmp(entry, RelocInfo::OFF_HEAP_TARGET);
                return;
            }
        }
        DCHECK(RelocInfo::IsCodeTarget(rmode));
        jmp(code_object, rmode);
    }

    void TurboAssembler::RetpolineCall(Register reg)
    {
        Label setup_return, setup_target, inner_indirect_branch, capture_spec;

        jmp(&setup_return); // Jump past the entire retpoline below.

        bind(&inner_indirect_branch);
        call(&setup_target);

        bind(&capture_spec);
        pause();
        jmp(&capture_spec);

        bind(&setup_target);
        mov(Operand(esp, 0), reg);
        ret(0);

        bind(&setup_return);
        call(&inner_indirect_branch); // Callee will return after this instruction.
    }

    void TurboAssembler::RetpolineCall(Address destination, RelocInfo::Mode rmode)
    {
        Label setup_return, setup_target, inner_indirect_branch, capture_spec;

        jmp(&setup_return); // Jump past the entire retpoline below.

        bind(&inner_indirect_branch);
        call(&setup_target);

        bind(&capture_spec);
        pause();
        jmp(&capture_spec);

        bind(&setup_target);
        mov(Operand(esp, 0), destination, rmode);
        ret(0);

        bind(&setup_return);
        call(&inner_indirect_branch); // Callee will return after this instruction.
    }

    void TurboAssembler::RetpolineJump(Register reg)
    {
        Label setup_target, capture_spec;

        call(&setup_target);

        bind(&capture_spec);
        pause();
        jmp(&capture_spec);

        bind(&setup_target);
        mov(Operand(esp, 0), reg);
        ret(0);
    }

    void TurboAssembler::CheckPageFlag(Register object, Register scratch, int mask,
        Condition cc, Label* condition_met,
        Label::Distance condition_met_distance)
    {
        DCHECK(cc == zero || cc == not_zero);
        if (scratch == object) {
            and_(scratch, Immediate(~kPageAlignmentMask));
        } else {
            mov(scratch, Immediate(~kPageAlignmentMask));
            and_(scratch, object);
        }
        if (mask < (1 << kBitsPerByte)) {
            test_b(Operand(scratch, MemoryChunk::kFlagsOffset), Immediate(mask));
        } else {
            test(Operand(scratch, MemoryChunk::kFlagsOffset), Immediate(mask));
        }
        j(cc, condition_met, condition_met_distance);
    }

    void TurboAssembler::ComputeCodeStartAddress(Register dst)
    {
        // In order to get the address of the current instruction, we first need
        // to use a call and then use a pop, thus pushing the return address to
        // the stack and then popping it into the register.
        Label current;
        call(&current);
        int pc = pc_offset();
        bind(&current);
        pop(dst);
        if (pc != 0) {
            sub(dst, Immediate(pc));
        }
    }

    void TurboAssembler::CallForDeoptimization(Address target, int deopt_id)
    {
        NoRootArrayScope no_root_array(this);
        // Save the deopt id in ebx (we don't need the roots array from now on).
        mov(ebx, deopt_id);
        call(target, RelocInfo::RUNTIME_ENTRY);
    }

} // namespace internal
} // namespace v8

#endif // V8_TARGET_ARCH_IA32
